Sealed unit



March 28, 1939. M. w. KENNEY ET AL 2,152,056

SEALED UNIT Filed May 10, 1934 3 Sheets-Sheet l March 28, 1939. M. w; KENNEY ET AL SEALED-UNIT Filed May 10, 1934 3 Sheets-Sheet 2 March 28, 1939. w NNEY T' 2,152,056

SEALED UNIT Filed May 10, 1934 5 Sheets-Sheet 3 Patented Mar. 281 1939 UNITED, STATES PATENT OFFICE SEALED UNIT Application 10, 1934, Serial No. 724,894

2 Claims.

Our invention relates in general to fluid forcing devices, and has more particular reference to rotary compressors.

The inventionhas for an important object the ,5 provision of an improved device particularly well adapted for incorporation as fluid forcing or compressing means in a refrigerating system more especially a system of the so-called compressionevaporation type, wherein a suitable refrigerating medium in gaseous condition is compressed, then liquefied by condensation, and finally evaporated for the absorption of heat, the gases evolved by the evaporation of the refrigerating medium being then returned to the compressor for a repetition of the refrigerating cycle.

Another important object is to provide fluid forcing mechanism of the character mentioned which is compact, efficient, and substantially noiseless in operation, and completely sealed against the escape of the Working medium, the device having self-contained means for adequately lubricating the mechanism, whereby the same is adapted for continuous operation over long periods of time without attention, and hence may be used to advantage in domestic refrigerators.

Another object is to provide a motor-compressor unit enclosed in a hermetic housing forming a compressor compartment and an adjacent motor compartment into which the compressor delivers the working medium and from which the working medium is discharged from the unit.

Another object is to provide a motor-compressor unit of the character mentioned wherein the com pressor is formed with means for circulating a lubricating medium to the Working parts of the compressor as well as to the journals of the motor, and wherein the working medium is circulated in the motor housing during the operation of the unit.

Another object is to provide a motor-compressor unit including a compressor and an adjacent motor enclosed in a hermetic casing forming a sealed housing for the unit, and having internal partition means defining. in the housing, a motor compartment and a compressor -compartment, wherein said partition affords a bearing for a shaft to which the rotating compressor and motor elements are drivingly connected; a further object being to provide a lubricant reservoir in the compressor compartment, and to provide the partition with lubricant channels through which lubricant from the reservoir may be forced through the bearing and into the motor compartment; and a still further object being to form said partition with means forming an overflow return from the motor compartment to the lubricant reservoir in the compressor compartment.

Another object is to provide a motor-compressor unit including a compressor and an adjacent motor enclosed in a hermetic casing forming a sealed housing for the unit, and having an internal partition defining in the housing a motor compartment and a compressor compartment wherein said partition contains a channel forming an inlet for the working medium to'the suction side of the compressor; a further object being to provide valve means at said channel in the partition, permitting the working medium to flow through said channel in one direction only.

Another object is to provide a motor-compressor unit including a compressor and an adjacent motor enclosed in a hermetic casing forming a sealed housing for the unit, and having an internal partition defining, in the housing, a motorcompartment and a compressor compartment wherein said partition provides a support on which stationary portions of the mot-or are mounted within the motor compartment; a further object being to journal the rotating portions of the motor and compressor in said partition and to support the stationary portions of the compressor on said partition; 2. still further object being to journal the rotating part of the compressor at one end in the stationary part of the compressor, and to immerse the lower portion of the compressor in a lubricant bath contained in the compressor casing, and to form said journal as a pumping means for delivering lubricant from said bath to the working parts of the compressor.

Another important object is to provide a fluid forcing device or compressor having a relatively stationary casing and a movable fluid-forcing element in said casing wherein the casing is formed with an internal chamber providing a mufller into which the working medium is delivered under pressure by the fluid forcing element; a further object being to form the muflier as a chamber cored in the compressor casing.

Another object is to provide a fluid forcing de- -vice or compressor comprising a casing open at one end and having a partition affording a compressor chamber and a mufller chamber, a cover for said chambers, and means in said compressor chamber forming a compressor comprising a cylinder formed with a discharge manifold and a fluid-forcing element in said cylinder, wherein said cover is provided with a channel connecting the muffler chamber with the discharge manifold; a further object being to provide means affording an outlet from the mufller chamber through said cover; and a still further object being to form said outlet as a pipe carried in and extending through said cover, and having an end extending adjacent the bottom of said manifold chamber.

Another object is to provide a fluid-forcing de vice or compressor having a casing containing a channel for a fluid working medium communicating with said compressor, and a valve operatively arranged in said channel and adapted to permit the working medium to flow through the channel in one direction only; a further object being to form said valve as a disk loosely confined in said channel in position to overlie a valve seat, said channel being enlarged in the vicinity of said valve seat to receive said disk and said valve structure including adjustable means to restrict the movement of said disk away from said valve seat; and a still further object being to form said seat to permit said disk to tilt thereon and to form the seat as a readily removable and replaceable fitting mounted in the compressor casing.

Another important object is to provide a compression expansion refrigerating system including a sealed motor compressor unit having the functional and structural advantages and characteristics hereinafter set forth. 7

These and numerous other objects, inherent advantages and functions of the invention will be apparent as the same is more fully understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment of the invention.

Referring to the drawings:

Figure 1 is a diagramm pressor evaporation reirig a sealed motor-compressor unit Cli'iisi) present invention;

Figure 2 is a View in horizontal section taken substantially along the line i"5--2 in Figure 3.;

Figure 3 is a view in vcrt cal section taken substantially along the line in Figure 2;

Figure 4 is a view in hori substantially along the line Figure 5 is a view in lzo substantially along the line Figure 6 is a view in vcrtic stantially along the line Figure 'I is a view in substantially along the line L? in .igure 2:

Figure 8 is a view in ve iral section taken snbstantially along the li Figure 9 is a diagramm system which may be used to operating a refrigerating system embodying our invention.

To illustrate our invention, we have shown on the drawings a fluid-forcing device particularly adapted for use as a compressor in a refrigerating system of the compression evaporation type, al-

though it will be obvious that the invention is not necessarily restricted to compressors or devices used in refrigerat ng systems. On the contrary, our present invention includes features which may be incorporated in hydraulic devices other than compressors and adapted for other uses than fluid-forcing means in a refrigerating system. We propose the devices of our present invention, however, as more particularly applicable as fluidforcing means adapted for substantially noiseless, leakproof and efdcient operation over long periods of time without attention, whereby the same is particularly well adapted for use in refrigerating systems wherein the stated characteristics are desirable. To provide the foregoing characteristics, we form the compressor as a sealed unit 9 including fluid-forcing means H and driving means l3 comprising an electric motor, housed in a substantially hermeticcasing 11. The casing may of course be formed in any suitable or preferred fashion, but we prefer to form the casing in sections, oneof which I9, is preferably formed as a casting having an outstanding peripheral flange 23 and providing a receptacle for the fluid-forcing element of the unit while the other casing section 2| is formed preferably of sheet metal and is of dome-like form affording a closure for the motor, said casing portion 2i having a peripheral flange 25 fastened as by a holding ring 26 and bolts 24 to a seat 22 formed in the flange 23 with an annular gasket 31 extending between the flanges whereby the casing portions are sealingly secured together in position to enclose the fluid-forcing and driving elements.

The casing portion I9 is formed with a partition 26' defining a chamber 21 adapted to receive the fluid-forcing or compressor mechanism II and a second chamber 29 forming a muffler, both of said chambers opening at one end of the casing portion. The casing portion 19 also carries a cover member 3 I which extends across and closes the open ends of the chambers 21 and 29, said cover member being secured in place on the casing portion it by means of bolts 33, suitable gasket means 35 extending between and being ap rarent, iorr a partition se aratinc:

driving means and the fluid-lo" e respectively mounted so that the former superposed upon the latter, the driving be re mounted on and supported by and ore l r 3i, while the fluid-fore means t is H o and supported by 1d below id superposed arrangement being nlarly well adapted to our purpose in. that it facilitates assembly and lubrication of the operating parts.

The fluid-forcing mechanism ll comprises a stationary element 41, which is preferably formed as an open ended sleeve, having an internal cylindrical bore 49, relieved as at 5! to form an inlet port. A duct 53 is formed in the walls of the member 41 between said inlet port and an end of the member. The walls of the element 41 are also formed with a channel 54 preferably extending parallel with the axis of the bore 49 and opening at the opposite ends of element 41, said channel 54 having communication with the bore 49 through ducts 55, which are drilled through the intervening portions of the element 41 at angles as shown in Figure '7, an expedient permitting the ducts 55 to be formed easily by means of a drill applied through the opposite ends of the bore 49.

The ducts 55 and the channel 5t form an ex to mount them on. the cover 31, "which,

the element 41, is supported upon the underside of the cover 3| by means of studs 59 which extend through the cover 51 and through bolt holes 6| formed in the element 41 and thread into sockets 63 formed in thecover 3|. The fluid-forcing element 65 comprises a cylindrical rotor which is mounted within the work chamber formed by the bore 49 between the facing surfaces of the cover members 3| and 51. This rotor is of less diameter than the interior of the bore 49 and is journaled for rotation within the work chamber about an axis eccentric with respect to the axis of the work chamber, the rotor being so positioned in the chamber that it forms running contact as at 61 with the walls of the work chamber between the inlet port and the exhaust manifold 54. The rotor is formed with an axial projection 69 at one end by which'it is journaled in the cover plate 51, said cover plate being formed with bearing means 1| for journaling said projection 69. The rotor also, at its opposite end, is provided with an axial projection forming a shaft 13 extending through and journaled in the cover v3|, which is formed with suitable bearing means 15 for receiving said shaft. The rotor 65 is provided with a plurality of channels 11 extending parallel with and spaced from the axis of the rotor and slots 19 are formed in the body of the rotor radially of said channels and tangential to a circle concentrio with the axis of the rotor and connecting the channels within the surface of the rotor 65, said slots extending from end to end of said rotor; The rotor also is undercut at its opposite ends to form annular channels 8| encircling the shaft projections and communicating with said channels 11. A fluid-forcing vane or blade 83 is arranged in each of the slots 19, said blades being long enough to engage the facing surfaces of the cover members 3| and 51' at their opposite ends and being slidable in the slots 19 in a tangential direction so that their outer edges, which are slightly rounded (as shown in Figure 5) may engage and press upon the inner surface of the bore 49 at all times during the rotationof the element 65 within the working cylinder. The

driving means I3 is operatively connected with the shaft 13, and is adapted to rotate the member 65 witliin the working chamber in the direction illustrated by the arrow in Figure 5, so that the blades 83, in traveling with the rotating element, will force fluid,- delivered in the working cham ber at the inlet 5|, through the chamber and deliver the same under pressure at the discharge manifold 54. The blades 83, however, are freely depressible in the slots 19 in order to permit fluid slippage at any time when abnormal pressures develop as where incompressible liquids enter the cylinder. This construction is adapted to relieve locking of the device and the consequent strain set up in the apparatus under such conditions. .The blade construction, which we have provided, also is adapted to relieve back pressure upon the rotor when the same is initially started in operation from rest. When the rotor commences to move, the inertia of the blades, together with the tangential arrangement of the same, causes the blades to slide inwardly in the slots 19, thus pro-'- viding a space between the outer edges of the blades and the inner working surface of thework cylinder, which unloads the pump at the instant of starting. As the speed of the rotor increases, centrifugal action expels the blades outwardly in the slot 19 into working contact with the cylinder walls so that the device becomes loaded as it reaches normal operating speed.

The lower edge of the sleeve 41 is relieved opposite the ducts 55 to provide a space 86 between the plate 51 and the abutting end of the sleeve,

the blades in order to assist the centrifugal ac-- tion, particularly when the rotor is turning at low speed, in holding the blades out against the wall 4|. If desired, a valve seat 94, ball valve 88 and spring 92 may be arranged in the socket to prevent the application of pressure behind the blades until the pressure developed at the discharge is sufficient to depress the check valve 88 whereby pressure is not applied behind the blades at starting.

The cover plate 3| is formed with an inlet duct 85 which is positioned to communicate with the channel 53 leading to the inlet port. The channel 85 extends radially outwardly in the cover 3| and opens at' the edge of the cover member. The channel 85 is enlarged inwardly of its open end to provide a substantially spherical valve chamber 81, a substantially circular opening 89 being formed between the valve chamberv 81 and the lower surface of the plate 3|, which is in contact with the casing portion I9. An annular valve seat 9| facing into the chamber 81 is secured in any suitable fashion in the opening 89, and a preferably circular disk 93 having a dimension substantially in excess of the dimension of the channel 85 is arranged in the valve chamber 81 in position to overlie the valve seat. The disk 93 is loosely confined within the chamber 81 and may move upwardly to uncover the valve seat and permit the passage of a working medium through the annular seat and into the channel 85. The disk, however, is normally gravity-actuated toward valve closing position on the seat and serves to prevent the passage of the work medium in a reverse direction. The casing |9.is provided with a neck 95 having a channel .91 communicating at one end with the annular valve seat and the neck 95 is provided with means-99 for connecting the movement to the position shown in dotted lines in Figure 3. v

The cover plate 3| is also formed with channel means I05 communicating the exhaust manifold 54 with the muilier chamber 29 so that the fluid, delivered in the manifold by the forcing element 65, may be dischargedinto the manifold, and

the cover 3| is provided with a fitting comprising a pipe I01 and a nipple I05 having an end opening near the bottom of the muffler chamber and I sure into the muiiler, through the exhaust manifold and the connecting conduit I05, may escape into the casingportion 2| above the cover 3|. The casing portion 2| is provided with means forming an outlet fitting III9 through which the compressed medium may leave the unit.

In order to provide adequate lubrication for the operating parts of the compressor, the same may be assembled with a quantity of a suitable fluid lubricant forming a lubricant pool I I I within the casing I9, said pool being so arranged that the lower end of the fluid forcing element II is immersed therein. The bearing 1| is formed with an internal spiral groove I I3 communicating at one end with the lubricant pool, and at the other with the interior of the cylinder in the vicinity of the annular groove 8| at the lower end of the rotor 65. A suitable screen H5 is mounted on the cover plate 51 in position to overlie the end of the groove H3 in order to strain the lubricant delivered from the pool to the groove. As soon as the fluid forcing element starts in operation, the suction created thereby will become effective in the groove H3 and will draw lubricant into the chamber at the lower end of the rotor. The groove 3 need not necessarily be formed in the bearing 1|, but may be formed as a separate channel through-the body of the plate 51, the advantage of forming the groove in the bearing being that the passage of the lubricant therethrough will also lubricat' the hearing. The lubricant thus delivered at the lower end of the rotor in the vicinity of the groove 8| will pass upwardly through the channels 11 of therotor into the annular groove 8| at the upper end thereof; The cover plate 3| is provided with a. lubricant duct II1, one end of which communicates with the upper groove 8| of the rotor and the other end of which communicates with the interior of the casing 2|. The duct H1 is preferably formed in the bearing and a perforation II9 communicates the channel II1 with the in terior of said bearing. The shaft 13 is preferably provided with a bushing |2I where it extends through the bearing 15, the outer surfaces of said bushing having a groove I23 formed so as to pump the lubricant received in the bearing at the groove I I9 toward the opposite ends of the bearing 15 in order to provide adequate bearing lubrication. Some of the oil thus pumped through the bearing overflows into the space within the casing 2| at the upper end of the bearing, while the remainder passes from the lower end of the bearing into the upper groove M of the rotor.

Some of the lubricant, in passing through the channels 11, flows outwardly through the slots 19, enters the working chamber and lubricates the blades 33 in order to reduce friction between the blades and the sides of the slots 19 and between the blades and the walls of the bore 49 as well as to form a fluid seal at these points. Some of the lubricant, thus delivered from the working chamber, will be delivered in the exhaust manifold with the compressed working medium. Where the working medium is in gaseous form, as in the case when the device of our invention is used as a part of a compression evaporation refrigerating system, the lubricant forced to the discharge manifold may be in finely divided condition entrained with the compressed. gases. We prefer to use dichloromethane as a refrigerant working medium, and the lubricant, especially if a mineral oil is used, will not dissolve to any appreciable extent in this refrigerating medium.

The finely divided lubricant, received in the exhaust manifold, is carried thence into the conduit means III5 and collects in the upper portions thereof. A duct I is formed in the bearing 15 in position to communicate the upper portion of the conduit means I05 with the interior of the bearing in the vicinity of the oil pumping grooves I23, so that the pumping action exerted by said grooves will draw the lubricant, collecting in the upper portion of the channel means I05, into the bearing for assisting in the lubrication of the same. The lubricant delivered in the bearing through the duct I 25 is pumped in opposite directions through the bearing by the action of the grooves I23 and is discharged at the opposite ends of the hearing as previously described. The lubricant delivered into the interior of the casing portion 2| through the channel II1 and through the upper end of the bearing 15, collects in a pool. as indicated at I21, above the flange 23 and the peripheral portions of the plate 3|. The plate 3| is provided with a return drain I29, shown in Figure 6, through which the lubricant may be conducted from tne pool I21 back to the reservoir III, within the casing I9, whenever the lubricant in the .pool I21 rises above a predetermined level. The drain I29 comprises a preferably cylindrical fitting having an axial channel I3I, said fitting being mounted at its lower end in a perforation I33 formed in the peripheral portions of the plate 3|. The fitting also has radial channels I35 formed in its sides above the plate 3| and a strainer, comprising a preferably cylindrical screen of pervious material, such as wire net I31, is secured in position on the fitting to cover the perforations I35, said screen being held in place on the fitting between the grooved peripheral edges I39 of spaced imperforate preferably sheet metal disks I32 mounted on and secured to the fitting above and below its perforations I35. As long as the level of the lubricant pool I21 is between the disks I32, lubricant will be strained through the screen I31 and passing the perforations I35 will drain through the channel I 3| into the reservoir I I I in the casing portion I9. Should the level of the pool I21, for any reason, riseabove the fitting I29, as for instance, because of the clogging of the screen I31, the lubricant may return tothe reservoir III directly through the channel |3| which opens at its upper end into the interior of the casing 2I, whereby to afford a direct communication between the casing 2| and the interior of the casing portion I9. We also provide the cover plate 3| with an embossment |4I having a channel I43 opening within the casing I9 at one end and within the casing I2I at the other at an elevation substantially above that at which the channel I3I of the drain fitting opens into the casing 2|, said channel I43 being for the purpose of equalizing the pressure within the casing portions I9 and 2|.

The driving means I3 may be of any suitable form-0r construction, but we have, to illustrate our invention, shown an electric motor having a J stator I45 carried on upstanding arms I41 formed -I5I and threaded into sockets I63 tapped into the cover plate 9|. The driving means has a rotor I65 drivingly connected to the shaft, 13, the motor rotor I65 being preferably secured directly on the end of the shaft projecting upwardly of the bearing in co-axial alignment with the annular stator. I45. The rotor I65 comprises a central spider I61 having an axial tapered socket I69 for receiving the correspondingly tapered end the spider and secured on the extremities of the arms I11, thus providing air channels I8I through the rotor in an axial direction. The rotor also carries fan blades I83 preferably stamped from a suitable lightweight sheet metal stock and secured on the rotor by means of the bolt I13. Obviously any suitable or preferred motor construction may be employed, but we have shown and prefer to use an alternating current capacitor motor and to power the same by means of conductors I85 adapted for connection with an external source of electrical power and entering the sealed unit through sealed inlet plugs I81 mounted in the flange 23 between the outer edge of the plate 3I and the seat 22 on which the edges of the casing 2| are secured. The inlet plugs I81 may-comprise substantially cylindrical sleeves I89 having externally threaded ends I9I fitting into internally threaded perforations formed in the flange 23, the conductors I 85 extending through said sleeves, the interior of which around said conductors is filled with a suitable sealing and insulating material I93.

When the device is in operation, the rotation of the rotor I65 will cause a circulation, within the casing 2I, of the compressed gases delivered therein by the fluid-fd'rcing mechanism, which circulation is assisted by the fan I83. The compressed gases are thus caused to travel in and around the operating parts of the motor and sweep across the interior surfaces of the casing portion 2I passing through the channels I8I and operating as a heat-transfer medium to absorb heat generated by the motor and deliver the absorbed heat to the casing 2i, which being of heat conducting character will" dissipate heat readily into the surrounding atmosphere. We may, of course, provide the casing 2| with means, such as fins for increasing the heat dissipated by the casing 2 I, but find that this is not essentialto satisfactory operation of the device.

As heretofore mentioned, the device of our present invention is particularly well adapted for use as a compressor in a refrigerating system.

To this end, the outlet fitting I09 may be connected as by a pipe or conduit I95 with a condenser I91 in which the compressed gaseous refrigerating medium delivered from the sealed unit is or may be condensed to liquid form, said condenser being of any suitable or preferred conrefrigerant is or may be delivered through a conduit 201 to a refrigerant evaporator or boiler 209 of any suitable or preferred construction,

in which the liquid refrigerant is evaporated to gaseous form, heat being absorbed at the boiler during the evaporating process. The evaporated refrigerant may be'returned from the evaporator to the inlet connection 99 of the sealed unit through a-suitable conduit 2| I, thus completing the refrigerating cycle. Such a system is particularly adapted for use in domestic refrigerators in which the elements of the system are mounted in a suitable cabinet indicated generally at 2I3, which cabinet includes arefrigerating compartment 2I5 and a mechanism compartment 2", the evaporator 209 being located in heat exchange relationship with the atmosphere of the refrig erating compartment, while the unit 9, the con denser I91 and its cooling fan motor I and the float control expansion valve 205 bein located in the mechanism chamber M1, the evices so located in the mechanism chamber being preferably mounted on a common support 45 to be assembled in or removed from the mechanism chamber as a single assembly unit, in order to facilitate manufacture of the refrigerator and the repair and replacement of the operating parts of the system. With such an arrangement, the conduits 201 and 2 may be permanently built into the walls of the cabinet during the course of its construction and the boiler 209 and the parts mounted on the support 45 assembled in place after the cabinet has been fabricated.

Where the unit 9 is incorporated in a refrigerating system, as aforesaid, we prefer to operate the motors I3 and 20I in parallel by means of an electrical control system substantially as shown in Figure 2 of the drawings. To this end, we prefer to form the motors so that the same may be operated in parallel, each motor preferably having a plurality of like windings 2I9 and 22I, The windings of each motor areconnected together at one end to a common conductor 223. The opposite ends of the windings 2| 9 of each motor also are connected together by a common conductor and the free ends of the windings 22! of each motor are likewise connected toa com-' mon conductor 221. The common conductor 223 is connected to a terminal 229 located in a casing 23L which is or may be located in any c0n-- venientpreferred position as on the support 45. From the terminal 229 the conductor 223 is connected by means of a conductor 233 forming a part of a cable 235 which extends in the refrigerator cabinet from the casing 23I to a thermostat control casing 231 located adjacent the evaporator 209. The opposite ends of the cable 235 may be provided with detachable connections 239 and 2M to facilitate the assembly of the parts in the cabinet. The conductor 233 when the parts are assembled and connected for operation. is connected to one side of a switch 243 preferably located in the casing 231 wh ch switch is opened and closed in response to thermostat means manually adjustable as by means of the ,7

control knob 244 preferably mounted on the casing 231, and including the thermostatic eleroent 245, which extends in heat exchange relationship with the atmosphere of the refrigerating compartment 2H5, so that the switch-243 is opened and closed automatically in response to temperature chamber. The other side of the switch 243 is connected through a manually operable switch 241 preferably mounted on the casing 291 and variations within the refrigeratingcluding the motor windings 219.

through a conductor 249 forming a part of the cable 235 to a terminal 251 in the casing 231. The terminal 251 is connected by a conductor forming a part of a cable 253 with means 253 preferably in the form of an electric plug or ordinary construction, and adapted for removable insertion in a power outlet socket such as is usually provided in commercial or domestic electric power systems. The cable 253 has another conductor adapted for detachable connection in the external power delivery circuit, which conductor is connected with a terminal 251 in the casing 231. This terminal 251 is electrically connected with one end of a solenoid 259 which is also located within the casing 231, the other end of. the solenoid being connected with a terminal 261 arranged within the casing 231, and to which the common conductor 221 is connected.

When the plug 255 is connected to an external- 'the switches 243 and 241, and the conductor 249.

In parallel with the portion of this circuit, which includes the solenoid winding 259 and the motor windings 221, is an additional circuit including a winding comprising an induction coil 263, the opposite ends of which are connected together through a condenser 265, and by means of a conductor 261 to the terminal 251 on one side of the solenoid 259, the induction coil 263 having taps 269 and 211 connected to stationary contacts 213 and 215 and a shiftable blade 211, which is movable in response to the current flowing through thesolenoid 259 and is adapted to selectively connect the contacts 213 and 215 to the conductor 225, and thence through the windings 219 of the motors in parallel to the common conductor 223.

The blade 211 is adapted to vary the reactive effect of the net work comprising the induction coil 263 and, the condenser 265 in the circuit, in-

The motors preferably employed are of the so-called capacitor-induction motors, the windings comprising split phase windings whereby the motors may be started in operation from standstill position when energized with single phase alternating current applied between the terminals 251 and 251. It will be noted that both of the parallel circuits including the motor windings 219 and 221 are controlled by the switches 243 and 241 so that when the plug 255 is connected to a power outlet, the motors will remain inactive until both of the switches 243 and 2 11 are closed. The switch 241, being manually operable, affords manual control for the motor, while the switch 243 provides for'automatic control so that the motors may be placed in operation when the temperature within, the refrigerating compartment 215 rises above a predetermined value, which may be determined by means of the knob 244. -When the plug 255 is connected with an external power source, alternating current will be delivered through the parallel circuits heretofore mentioned, and which include the several windings of the motors. The current delivered to the windings 219, however, will have a different phase relationship with respect to that delivered to. the windings 221, because of the reactive effect provided by the induction coil 263 and the condenser 265 so that. a rotating field may be created in the motor for the purpose of starting the same. At the instant of starting, the switch 211 will engage one or other of the contacts 213, 215 so that the proper phase relationship to start the motors will exist between the current delivered to the motor windings 219 and 221. As the motors reach normal operating speed, the switch 211 will be moved under the influence of the coil 259, and will engage the other of said contacts 213, 215, in order to alter the reactive efiect provided in the current flowing to the motor windings 219 in order to afford a desired phase relationship between the current ,from that required after the motors have reached normal operating speed.

The electrical system also includes a circuit 219 including'a lamp 281 and a switch 283, said circuit being connected between the conductor 249 of the cable 235 and another conductor 285 contained in said cable and connected to the terminal 251 so that whenever the plug 255 is connected to the external power source, the lamp 291 will be energized providing the switch 283 is closed. The lamp 281 is or may be arranged in any suitable or convenient position within the compartment 215 while the switch 283 is arranged to cooperate with the doors usually provided in domestic refrigerators for giving access to the compartment 215. The door, when closed, cooperates with the switch to hold the same in open position. When the door is open, however, the switch is permitted to close so that the lamp 231 will illuminate the interior of the compartment 215 whenever the door is open.

It is thought that the invention and numerous of its attendant advantages will be understood from the foregoing description, and it is obvious that numerous changes may be made in the form,

construction, and arrangement of the several parts without departing from the spirit or scope of my invention, or sacrificing any of its attendant advantages; the forms herein described being preferred embodiments for the purpose of illustrating my invention.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is as follows:

1. A device of the class described comprising a pair of casing elements, means to secure said elements together to form a housing, partition meansforming a support in said housing and defining compartments on opposite sides of the partition means, relatively movable fluid-forcing elements carried by said partition within one of the compartments, and motor means carried by the partition within the other compartment, a drive shaft journalled in and extending through said partition and operatively connected with the motor means and the fluid-forcing means on opposite sides of the partition, means for admitting fluid through the walls of said casing to said fluidforcing means, including a duct in a wall of one of the casing elements communicating with a duct in said partition, the latter duct in turn conmeeting with the suction side of the fluid-forcing means, means forming a check valve in said partition substantially at the point of communication of said ducts, one of the ducts opening upon a seat, and a disk in said chamber adapted to overlie the seat provided by said fitting.

2. In a device of the class described, a pair of casing elements, means to secure said elements together to form a housing, partition means forming a support in said housing and defining-compartments on opposite sides of the partition, relatively movable fluid-forcing elements carried by said partition within one of the compartments, and motor means carried by the partition within the other compartment, said fluid-forcing means being adapted upon operation of the motor to deliver a fluid work medium, under pressure, and a lubricating medium into said motor compartment,

15 said motor compartment having an outlet for ment, the opposed ends of said tubular element opening one in the motor compartment and the other in the chamber containing the fluid-forcing means, lateral openings in said tubular element within the motor compartment and screen means covering said lateral openings.

-MAHLON W. KENNEY.

ARTHUR R. CONSTANTIN'E. 

